Next-generation communication systems need to maximize data rates thereof and meet various needs of users in an ever-changing channel environment. To this end, a need is being emphasized for channel codes having a strong error correction capability, thereby raising a performance level required for the channel codes.
A Low-Density Parity-Check (LDPC) code proposed by Gallager in 1962 is known as having superior performance that is close to a channel capacity of Shannon through repetitive decoding. However, for a binary LDPC code, a code length N has to be sufficiently long to obtain performance that is close to the channel capacity of Shannon. When an LDPC code is designed in a non-binary finite field, performance that is close to a channel capacity may be obtained for a relatively short length, and for a codeword length considered in an actual communication system, superior performance may be provided when compared to a binary LDPC code. As the non-binary LDPC code is known as providing better performance than a general binary LDPC coding scheme, the non-binary LDPC code is attracting much attention as one of channel codes suitable for next-generation communication systems.
A general non-binary coding scheme is configured to properly map one non-binary code to a signal constellation, thus maximizing performance. However, studies have not been conducted regarding a signal constellation mapping scheme when a plurality of coding schemes are used to support a service of various qualities.
Recently, various multimedia services are configured compositively, such that a number of attempts have been made to provide one new service. Because services need different qualities, research has been conducted to provide different robustness properties for different services. One of such methods for providing different qualities is to use a plurality of coding schemes. However, typically, one modulator and one demodulator are used for convenience of implementation in a system, such that for application of the plurality of encoding schemes to the system, a signal constellation mapping scheme suitable for the plurality of encoding schemes needs to be studied. In particular, as the non-binary encoding scheme has become important, a need is also increasing for studies on combining the non-binary encoding scheme with the signal constellation mapping scheme.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.